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[KP4CB]

I am looking for a web site of a ham that detailed the construction of this tower, with physcal measurment and angles. He used for the bending of the conduit some tool for small airplane construction.  I dont remember if he lived in California.

Thanks For any help

Athos
Kp4cb

[WA3SKN]

Before building any home made tower, check for any local building requirements.  Very few locations in the USA do not have them.

-Mike.

[K4GTE]

EMT and screws for tower construction ? This sounds like a recipe for disaster. Towers need to be welded.

[AI5BC]

EMT and screws for tower construction ? This sounds like a recipe for disaster. Towers need to be welded.

Sounds like an amateur radio tower to me.

[SWMAN]

 I think I saw one that Jethro Bodine made, it didn’t look real sturdy but it worked.

[N0GV]

A one word recommendation is: DON'T

If you can bend emt with a 4' long bender a 40 foot tall tower will bend it with 10% of the force you needed. Towers need to be certified by a licensed engineer for a number of reasons: (1) Code requirements, (2) Insurance carrier requirements, (3) Your neighbor's safety (if you are dumb enough to try what you asked then you are definitely trying for a Darwin award and that is your own business). 

Just don't do this!

Sincerely,

Grover

[K6JH]

There is a ham that makes couplers for fence rails, and a jack system to raise them. Perhaps that’s what you’re thinking of? Not so much a tower as a guyed mast system. I forget the call sign - probably have it bookmarked on my old computer somewhere, but you can probably Google it.

[WB6BYU]

The problem with conduit is that it is
designed to be bent.  That’s not a good
attribute for a tower.

Yes, I’m sure someone has built one - not
all hams are competent mechanical engineers.
The issue is not building it, but getting it
vertical and keeping it that way, especially
with any significant load of antennas on top.

[AI5BC]

Like a helicopter, twist and turn, crash and burn.

[KC3TEC]

Emt conduit is thin walled and lightweight
If building a square 4 legged tower with sufficient bracing and guy wires it's OK for a lightweight antenna with a very small wind resistance profile.
But not for a beam quad or yagi.

Welding while better electrically will weaken the surrounding metal.

If you are going to use conduit your better off using rigid conduit.

[K6JH]

This is the guy I was thinking of. It looks a little too spindly for me.

https://www.ke1q.com/

[VE7RF]

Yield strength of EMT tubing is very low.  It's low since it can be easily  bent.  EMT is the worse type of tubing you could use for tower legs. It will fold like an accordion.  You would be better off using angle steel, and making a 4 x sided tower.
Anything made from steel will have to be galvanized.  Anything made from aluminum is iffy, like aluminum emt conduit.

Cheapest, safest route would be to just buy new / used..... a real tower.  Then it's designed to a specific set of engineered specifications.

[VR2AX]

http://aerial-parts.co.uk/epages/626ba059-121d-45c5-8692-ea58514eb29c.mobile/en_GB/?ObjectPath=/Shops/626ba059-121d-45c5-8692-ea58514eb29c/Categories/750

[N2EY]

A one word recommendation is: DON'T

If you can bend emt with a 4' long bender a 40 foot tall tower will bend it with 10% of the force you needed. Towers need to be certified by a licensed engineer for a number of reasons: (1) Code requirements, (2) Insurance carrier requirements, (3) Your neighbor's safety (if you are dumb enough to try what you asked then you are definitely trying for a Darwin award and that is your own business). 

Just don't do this!

Sincerely,

Grover

WELL SAID!

It may be POSSIBLE to build a tower out of large-diameter EMT - if someone has the know-how to properly design it, calculate all the stresses and such, get the design checked and certified, and then properly fabricate it, with properly welded joints and hot-dip galvanizing.

But is that really the way to go? Particularly when genuine towers are available, complete with engineering documentation?

73 de Jim, N2EY

 

[KO4QLC]

ELECTRICAL CONSTRUCTION AND MAINTENANCE IS MY THING.  IF YOU ARE PURCHASEING THE CONDUIT, BE IT RIGID OR EMT, EITHER ONE SHOULD BE SUPOPORTED AT LEAST EVERY 10 FEET, AND WILL BE MORE EXPENSIVE THAN PURCHASEING AN ALUMINUM STANDARE TOWER.  THE HOME BREW TOWER IS NOT A GOOD IDEA.  ANYTHING OVER 20 FEET WILL BE A DESASTER.  THE STRENGTH IS JUST NOT THERE